Fig. 6. Analysis of the interaction of her7 with the aei (after eight), des (deadly seven), bea (beamter) and wit (white tail) mutations in the Delta/Notch signaling pathway. The myotome boundaries of the anterior trunk marked by twitchin expression are shown in 26 hpf embryos in lateral view, anterior towards the left and dorsal upwards (A-F). The expression of cyclic genes is shown in the presomitic mesoderm of embryos at 14 hpf (10 somites) in a dorsal view after flat mounting with anterior up (K-Y). (A) aei, (B) des and (C) bea uninjected; (D) aei, (E) des and (F) bea injected with 7 ng/µl her7m2. Arrows in A-F indicate the position of the anterior limit of segmental defects in each embryo. Scale bar in A: 50 µm for A-F. Histograms comparing the effect of her7m2 injection on the anterior limit of segmental defects at 26 hpf in aei (H), des (I), and bea (J) genetic backgrounds. In K-Y, a pair of embryos are shown, with uninjected on the left and injected (7 ng/µl her7m2) on the right (indicated with +). An average of 15 embryos injected with either her7m1 or her7m2 was analyzed per treatment. K-O, P-T and U-Y show the expression of dlc, her1 and her7, respectively, and the columns show the wild type (K,P,U), bea (L,Q,V), aei (M,R,W), des (N,S,X) and wit (O,T,Y) genetic backgrounds.